Mice in RV Underbelly? – 5 Methods to Be Sure

Mice are notorious for wreaking havoc on our homes. But don’t forgot about vehicles too.

RVs, in particular, are especially prone to mice infestations because they often remain stationary for longer periods of time and often contain pantries full of food.

Dealing with a mouse problem in your camper can be overwhelming and stressful, but it doesn’t need to be. Fortunately, being knowledgeable on this subject greatly reduces unwanted stress. So…let’s get into it.

How do mice get into RVs?

Like homes and other vehicles, RVs contain many entry points for rodents to enter through and many small, enclosed spaces for them to build a nest in.

Any small hole in a camper or trailer can be a possible entrance for mice. Common entry point areas in RVs are the underbelly, the shore power cord compartment, and openings above the wheels. Keep in mind that mice don’t require much room to wiggle through. A quarter inch diameter hole is large enough for them to squeeze through.

It’s important to do a thorough walkthrough of your camper, inside and out, and take note of all openings larger than or equal to a quarter inch diameter. Being aware of these entry points will help you prevent your mice from entering and could also help you locate their nest.

Top 5 Signs mice are in your RV

There are many possible ways to tell if mice are in your camper, and some ways are more obvious than others.

The most obvious way is by physically seeing a mouse inside your camper in the first place. If you see a mouse or two or three inside your RV, it’s pretty clear that you have rodents. The more often you see them or the more you see at once, the greater your problem is. Also, if you frequently spot them around the perimeter of the RV, it’s likely that you have a problem inside the RV, too.

However, as we all know, mice are elusive and very shy rodents. Many of them manage to go unseen, and so we are often left to depend on other ways to detect their presence. The best way to detect them without physically seeing them is to look for proof of mouse activity, and there a few great ways to do so:

Mouse droppings

Mouse droppings go wherever mice go. So, if you have mice in your camper, you will also have mouse droppings. While mice do a pretty good job of hiding themselves from us, they aren’t as careful with their poop. Their droppings are typically about a quarter inch in length. You can tell if they are fresh by the color: newer droppings are darker and shinier while older droppings look dusty and dry. Mice also tend to leave their droppings in larger concentrations in areas closer to their nest.


If you have mice, you probably have a mouse nest, too. Mice build their nests with whatever small, lightweight materials that they can get their little hands on. They typically shred and gnaw on paper, fabrics, small plastics, and other household materials to construct their nests. Look around the inside of your RV for evidence of shredded or gnawed on materials. Also, be sure to check your pantry, cabinets, closets, and recycling for any proof.


Mice aren’t known for their appealing smell. They’re known for just the opposite. Look out for musky, pungent odors that do not seem to have any other plausible origin. This stinky odor that you may notice is actually mostly mouse urine. If there is a dead mouse somewhere in the RV, the smell will be much more intense and overwhelmingly awful. It’s hard to mistake the smell of a dead animal for something else.

Mouse noises

Mice are noisy rodents. In most cases, they are silent crawlers (depending on the material that they crawl on), but in almost all cases, they are loud squeakers. Mice squeak to each other as a form of communication. They are loudest at dusk and dawn, although can be heard during the night. If you hear unusual, high pitched squeaks at night, it could be mice signing to each other.

RV damage

Unexpected or sudden damage to your RV may be a sign that you have mice. For example, if heat isn’t coming out of all the vents, mice could have chewed their way through the HVAC ducting causing to air to leak out of holes throughout the ducting. Mice also commonly chew on wires which may be noticeable if appliances start malfunctioning or if dashboard visuals appear static and incorrect.

How do I get rid of mice in my RV walls?

If you have determined that you have mice in your RV walls, your options are limited. You probably shouldn’t smash through the walls, as this will cause avoidable damage and be expensive to fix, so instead, you have to get creative.

The best thing to do is turn your camper or trailer into a hostile location unsuitable for mice live in. To do this, you must eliminate their food sources while also actively using mouse traps to capture or kill the ones that currently inhabit the RV.

Traps, traps, traps. I cannot emphasize the use of rodent traps enough…they work! Try using snap traps with peanut butter, humane mouse traps, or rodenticides (rodent poison). Peanut butter is the best bait known to attract mice. Traps posted near entry points also tend to yield the best results.

How do I protect my RV from mice?

Whether you currently have a rodent problem or not, it’s imperative to properly protect your camper in the first place to prevent mice from entering.

Food storage/cleaning

The most important thing you need to do is keep all food stored away properly. This involves cleaning up all food scraps and crumbs throughout your RV, storing all food in tightly sealed containers, and routinely cleaning your camper.

Steel wool

Take a peek at your RV’s entire perimeter and underbelly looking for any small holes that a mouse could get through. Steel wool works wonders for these small openings.

Seal all small holes with some steel wool (be sure to use regular steel wool, not steel wool soap pads). 

While steel wool acts as a great first barrier, it’s important to note that it’s sometimes possible for a some mouse to chew through it. This is rare, but should be noted in case it does happen.

Peppermint oil/cotton balls

Some people have claimed that peppermint oil can help keep mice and other rodents from entering a camper or RV. There is little evidence to back up this claim, but it’s worth trying out if you want to opt for an all natural repellent.

Because mice have an exceptional sense of smell, the thought is that peppermint oil’s very strong scent irritates their sensitive olfactory system and causes them to avoid areas in which the oil is concentrated in.

If you use this method, dampen a few cotton balls with peppermint oil and scatter the cotton balls near all suspected entry points inside your RV. Be sure to check and replace the balls frequently with cotton balls freshly soaked in peppermint oil. The oil will dissipate over time and thus the scent will lessen. Some people replace the peppermint balls daily, every other day, or once a week.

Also, peppermint oil can be toxic to dogs, cats, and other pets when ingested or absorbed by the skin.

So, please make sure to only place the oil only in areas that your pets cannot access!

What can I put under my house to keep mice away?

If you are concerned about your camper underbelly and the space underneath your house, first you must question your concern.

Are there actually openings large enough for a mouse to get through in theses locations? If not, then you shouldn’t bother messing around with these areas. If you do notice small entry points in and around the underbelly, plug all of the openings with steel wool. If there are substantially large openings or serious damage to the underbelly, you may have to have the entire surface re-sealed or replaced by a professional.

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